Dyes for photography

ABSTRACT

DYES DERIVED FROM 1 H-PYRAZOLO(3,2-C)-S-TRIAZOLES ARE ADVANTAGEOUSLY USED IN PHOTOGRAPHIC SOLVER HALIDE ELEMENTS AS LIGHT-ABSORBING DYES FOR FILTER LAYERS.

UhitdSfites Patent Office 3,810,761 DYES FOR PHOTOGRAPHY Joseph Bailey,Harrow Middlesex, and Edward B. Knott, Bushey Heath, England, and PeterA. Marr, Rochester, N.Y1. I :{ssignors to Eastman Kodak Company,Rochester,

No Drawing. Application Jan. 15, 1971, Ser. No. 106,893,

now Patent No. 3,758,309, which is a continuation-inpart of abandonedapplication Ser. No. 778,333, Nov. 22, 1968. Divided and thisapplication Dec. 7, 1972, Ser. No. 313,078

Claims priority, application Australia, Oct. 16, 1968,

44,870, 44,871; Belgium, Nov. 25, 1968, 66,581; Canada, Nov. 25, 1968,35,997, 35,998; France, Nov. 25, 1968, 175,097; Germany, Nov. 25, 1968,10,462

Int. Cl. G03c 1/84 U.S. CI. 96-84 R 19 Claims ABSTRACT OF THE DISCLOSUREDyes derived from 1H-pyrazolo[3,2-c]-s-triazoles are advantageously usedin photographic silver halide elements as light-absorbing dyes forfilter layers.

This application is a division of US. Ser. No. 106,893, filed Ian. 15,1971, now Pat. No. 3,758,309, which in turn was a continuation-in-partof US. Ser. No. 778,333, now abandoned.

The present invention relates to photography, including colorphotography, light-sensitive photographic emulsions containing a dyederived from a lH-pyrazolo[3,2-c]- s-triazole and light-sensitiveelements in which at least one layer contains a dye derived from a1H-pyrazolo[3,2- c]-s-triazole.

It is known that certain methine dyes, including certain cyanine dyesand certain merocyanine dyes are useful in photographic elements assilver halide sensitizer and/or as light-filtering dyes. Dyes thatspectrally sensitize silver halide emulsions are particularly valuablefor use in color photography to differently sensitize the emulsionlayers so they will record light from the desired parts of the visiblespectrum. Color photographic elements usually comprise a support coatedwith an emulsion sensitive to light from the red region of the spectrum,an emulsion sensitive to light from the green region of the spectrum andan emulsion that is sensitive to light from the blue region of thespectrum. The layers may be arranged in various orders, however, oneconventional arrangement is to have the redsensitive layer coated on thesupport with the green-sensitive layer coated next, and theblue-sensitive layer outermost, usually with a bleachable bluelight-absorbing filter layer coated the between the greenandblue-sensitive layers. In addition to the bleachable bluelight-absorbing filter layer, other light-absorbing layers are used,either over, between or under one or more of the light-sensitive layers.

Dyes must have not only the desired sensitizing characteristics and/orlight-absorbing characteristics but be readily soluble preferably inaqueous media for ease in sensitizing a photographic emulsion and alsofor ease in removal from the emulsion layers during photographicprocessing so that a minimum of stain is produced in the resultingphotograph. There is a continuing search for new dyes to fill the needsfor sensitizing and light-absorbing dyes for photography.

It is therefore an object of our invention to provide a novel class ofdyes derived from a lH-pyrazolo[3,2-c]-striazoles of the indicated typethat are valuable for use in photography as sensitizing dyes and/orlight-filtering dyes.

Another object of our invention is to provide a novel 3,810,761 PatentedMay 14, 1974 hydrophilic colloid silver halide emulsion containing oneof our methine dyes.

Another object of our invention is to provide a novel photographicelement comprising a support, at least one silver halide emulsion layerand at least one layer con taining a methine dye derived from a1H-pyrazolo[3,2-c]- s-triazole.

Still other objects will be apparent from a consideration of thefollowing specification and claims.

These and still other objects are accomplished according to ourinvention by the preparation and use of our novel dyes derived from alH-pyrazolo[3,2-c]-s-triazole. 'Our dyes have two nuclei, at least oneof them being a 1=H- pyrazolo[3,2-c]-s-triazole nucleus attached at thecarbon atom in the 7 position of this nucleus through a double bond orby a methine linkage to a second nucleus to complete the dye, such as, asecond lH-pyrazolo[3,2-c]-striazole nucleus, a heterocyclic basicnucleus having from 5 to 6 atoms in the heterocyclic ring in whichnitrogen, oxygen, sulfur and selenium are the heteroatoms with at leastone of the heteroatoms being nitrogen, including any of the well-knownheterocyclic nuclei found in cyanine dyes or an acidic heterocyclicketomethylene nucleus having from 5 to 6 atoms in the heterocyclic ringwith heteroatoms such as nitrogen, oxygen, sulfur and selenium,including any of the well-known acidic heterocyclic ketomethylene nucleifound in merocyanine dyes.

In one embodiment of our invention, our methine dyes have two1H-pyrazolo[3,2-c]-s-triazole nuclei connected to each other through thecarbon atom in the 7 position of the nuclei by a conjugated methinelinkage having an odd number of from 1 to 5 (i.e., 1,3 or 5) carbonatoms in the linkage.

In another embodiment of our invention, our dyes have alH-pyrazolo[3,2-c]-s-triazole nucleus attached at the carbon atom in the7 position of this nucleus through a double bond or a methine linkage toa carbon atom in a second nucleus that is a heterocyclic basic nucleushaving from 5 to 6 atoms in the heterocyclic ring such as are found incyanine dyes.

In another embodiment of our invention, our dyes have alH-pyrazolo[3,2-c]-s-triazole nucleus attached at the carbon atom in the7 position of this nucleus by a conjugated methine linkage having an oddnumber of from 1 to 5 (i.e., 1, 3 or 5) carbon atoms in the linkage, toa carbon atom in a second nucleus that is an acidic heterocyclicketomethylene nucleus having from 5 to 6 atoms in the heterocyclic ring,including any of the acidic heterocyclic ketomethylene nuclei found inmerocyanine dyes.

The dyes of our invention are derived from a 1H-pyrazolo[3,2-c]-s-triazole advantageously represented by the formulas:

wherein R, R R and R each represent the same or a dif ferent group, suchas, a hydrogen, an alkyl group that is straight chain or branched chain,preferably having from 1 to 22 carbon atoms and unsubstituted orsubstituted, such as, methyl, ethyl, n-propyl, isopropyl, sec. butyl,t-butyl, tamyl, hexyl, 2-chlorobutyl, 2-hydroxyethyl, '2-phenylethyl,2-(2,4,6-trichlorophenyl)ethyl, etc.; an aryl group that isunsubstituted or substituted, in which the aryl group is a naphthylgroup, e.g., (Z'Ha/Phthyl, p-naphthyl, 2-chlOl'O-7- naphthyl,2-methoxynaphthyl, etc., a phenyl group (e.g., 4-methylphenyl,2,4,6-triehlorophenyl, 3,5-dibromophenyl,

R o y:-

group; R represents an alkyl group (e.g., methyl, ethyl, butyl, etc.) oran aryl group (e.g., phenyl, tolyl, ethylphenyl, chlorophenyl, etc.; Rand R being additionally and individually defined as an alkylthio groupwherein the alkyl moiety usefully contains 1-20 carbon atoms,particularly lower alkyl exemplified by methyl and octyl.

R NH T i:

I and IIb. N

wherein R, R R and R are as defined previously, while Q and Q representthe atoms necessary to complete the chromophoric system. Q, for example,represents a group, etc., and Q, for example, represents a group, etc.,wherein L represents a methine group (e.g., -CD= where D representshydrogen, a lower alkyl group, such as, methyl, ethyl, butyl, etc., andan aryl group such as phenyl, tolyl, naphthyl, etc.) such that not morethan one L group contains a D group other than hydrogen; n represents aninteger of from 0 to 2; R and R are as described previously; Zrepresents the atoms necessary to complete a heterocyclic basic nucleushaving from 5 to 6 atoms in the heterocyclic ring such as thoseconventionally employed in cyanine dyes, especially including 2-pyrrole,3-pyrrole, 2-indole, 3-indole, 1-indolizine, 3-indolizine, etc.; Zrepresents the atoms necessary to complete an acidic heterocyclicketomethylene nucleus having from 5 to 6 atoms in the heterocyclic ringconventionally employed in merocyanine dyes, such as, a hydantoinnucleus (e.g., hydantoin, 3-alkyl (e.g., ethyl, propyl, etc.) hydantoin,3-phenyl or S-a-naphthyl hydan- 4 toin, 1,3-dialkyl (e.g., l,3-diethyl,etc.) hydantoin, l-alkyl-3-aryl (e.g., 1-methyl-3-phenyl,l-methyl-3-naphthyl, etc.) hydantoin, 1,3-diphenyl hydantoin, etc., athiohydantoin nucleus (e.g., 2-thiohydantoin, 3-methyl-2-thiohydantoin,1,3-diethyl 2 thiohydantoin, 1,3-diphenyl-2- thiohydantoin,1-ethyl-3-phenyl-2-thiohydantoin, etc.), a rhodanine nucleus (e.g.,rhodanine, 3-ethylrhodanine, 3- phenylrhodanine, 3-u-naphthylrhodanine,3-(l-benzothiazyl)rhodanine, etc.), a barbituric acid nucleus (e.g.,barbituric acid, l-ethyl barbituric acid, 1,3-diethyl barbituric acid,etc.), a thiobarbituric acid nucleus (e.g., 2- thiobarbituric acid,1-propyl-2-thiobarbituric acid, l-phenyl-Z-thiobarbituric acid,1,3-diethyl-2-thiobarbituric acid, etc.), a 2-thiazolin-4-one nucleus(e.g., 2-thiazoli n-4-one, 3-methyl-2-thiazolin-4-one, etc.), a2-thio-2,4-oxazolinedione nucleus (e.g., 2-thio-2,4-oxazolinedione,3-ethyl-2- thio-2,4-oxazolidinedione, etc.), an imidazolone nucleus(e.g., 2-imidazolin-4-one, etc.), a 2-pyrazolin-5-one nucleus (e.g.,Z-pyrazolin-S-one, I-phenyl-Z-pyrazolin-S- one,3-anilino-2-pyrazolin-5-one, etc.), an indandione nucleus (e.g.,indandione, etc.), etc.; Z represents the nonmetallic atoms required tocomplete a 5 to 6 membered heterocyclic basic nucleus of the type foundin cyanine dyes, such as, a thiazole nucleus (e.g., thiazole, 4-methylthiazole, 4-phenylthiazole, S-methylthiazole, 5-phenylthiazole, 4,5dimethylthiazole, 4,5 diphenylthiazole, 4-(2- thienyl) thiazole, etc.),a benzothiazole nucleus (e.g., benzothiazole, 4-chlorobenzothiazole,S-chlorobenzothiazole, 6 chlorobenzothiazole, 7 chlorobenothiazole, 4-methylbenzothiazole, S-methylbenzothiazole, 6-methylbenzothiazole,S-bromobenzothiazole, 6-bromobenzothiazole, 4-phenylbenzothiazole,S-phenylbenzothiazole, 4-methoxybenzothiazole, S-methoxybenzothiazole,6-methoxybenzothiazole, S-iodobenzothiazole, fi-iodobenzothiazole,4-ethoxybenzothiazole, S-ethoxybenzothiazole, tetrahydrobenzothiazole,5,6-dimethoxybenzothiazole, 5,6-dioxymethylenebenzothiazole, 5hydroxybenzothiazole, 6 hydroxybenzothiazole, etc.), a naphthothiazolenucleus (e.g., anaphthothiazole, fl-naphthothiazole,5-methoxy-m-naphthothiazole, S-ethoxy a naphthothiazole,-8-methoxy-flnaphthothiazole, 7-methoxy tit-naphthothiazole, etc.), athionaphtheno-7',6',4,5-thiazole nucleus (e.g.,4-methoxythianaphtheno-7',6',4,5-thiazole, etc.), an oxazole nucleus(e.g., 4-methyloxazole, S-methyloxazole, 4-phenyloxazole,4,5-diphenyloxazole, 4-ethyloxazole, 4,5-dimethyloxazole,S-phenyloxazole, etc.), a benzoxazole nucleus (e.g., benzoxazole,S-chlorobenzoxazole, S-methylbenzoxazole, S-phenylbenzoxazole,6-methylbenzoxazole, 5,6- dimethylbenzoxazole, 4,6 dimethylbenzoxazole,5 meethoxybenzoxazole, S-ethoxybenzoxazole, S-chlorobenzoxazole,6-methoxybenzoxazole, S-hydroxybenzoxazole, 6-hydroxybenzoxazole, etc.),a naphthoxazole nucleus (e.g., rat-naphthoxazole, ,B-naphthoxazole,etc.), a selenazole nucleus (e.g., 4-methylselenazolc,4-pheny1selenazole, etc.), a benzoselenazole nucleus (e.g.,benzoselenazole, S-chlorobenzoselenazole, S-methoxybenzoselenazole, 5-hydroxybenzoselenazole, tetrahydrobenzoselenazole, etc.), anaphthoselenazole nucleus (e.g., tat-naphthoselenazole,,B-naphthoselenazole, etc.), a thiazoline nucleus (e.g., thiazoline,4-methylthiazoline, etc.), a Z-pyridine nucleus (e.g., 2-pyridine,5-methyl-2-pyridine, etc.), a 4-pyridine nucleus (e.g., 4-pyridine,3-methyl-4-pyridine, etc.), a 2- quinoline nucleus (e.g., 2-quinoline,3-methyl-2-quinoline, 5-ethyl-2-quinoline, 6-chloro-2-quinoline,8-chloro- 2-quinoline, 6-methoxy-2-quinoline, 8-ethoxy-2-quinoline,8-hydroxy-2-quinoline, etc.), a 4-quinoline nucleus (e.g., 4-quinoline,6-methoxy-4-quinoline, 7-methyl-4-quinoline, 8-chloro-4-quinoline,etc.), a l-isoquinoline nucleus (e.g., l-isoquinoline,3,4-dihydro-l-isoquinoline, etc.), a 3-isoquinoline nucleus (e.g.,3-isoquinoline, etc.), a 3,3-dialkylindolenine nucleus (e.g.,3,3-dimethylindolenine, 3,3,5- trimethylindolenine,3,3,7-trimethylindolenine, etc.), an imidazole nucleus (e.g., imidazole,l-alkylimidazole, l-alkyl-4-phenylimidazole, l-alkyl 4,5dimethylimidazole, etc.), a benzimidazole nucleus (e.g., benzimidazole,l-al- III.

wherein R, R L, n, Z R and X are as defined previously, areadvantageously prepared by reaction of a compound of Formula Ia with acompound of the Formula V:

wherein L, n, 2, and R are as defined in the presence of an acid IIX.These dyes are advantageously used as filter dyes which are bleachablein photographic developer solutions.

Dyes of the Formula VI.

wherein R, R L, n and Z are as defined previously, are advantageouslyprepared by reaction of a compound of Formula I with a compound havingthe Formula VII:

VII. Z2

wherein Y is alkoxy or acetanilido. Dyes of Formula VI areadvantageously used to spectrally sensitize photographic silver halideemulsions.

6 Dyes of the Formula VIII:

VIII. R VN N l R1 wherein R, R L, n, R, and 2;, are as definedpreviously, are advantageously prepared by reaction of a compound ofFormula Ia with a compound of the Formula IX:

wherein Y is iodine, ethylthio, or an acetanilido radical. Dyes ofFormula VIII are advantageously used as spectral sensitizers for silverhalide emulsions.

The compounds of Formulas I and la are advantageously prepared byheating the appropriate 7-alkoxycarbonyl-lH-pyrazolo-[3,2-c]-s-triazolo(substituted or not on the carbon atoms in the 3 and *6 positions on thering) in sulfuric acid to remove the 7-alkoxycarbonyl group byhydrolysis. The 7-alkoxycarbonyl-l-H-pyrazolo [3,2-c1-s-triazoles areadvantageously prepared by adding a solution of bromine in glacialacetic acid to a mixture of benzaldehyde4-ethoxycarbonyl-3-methylpyrazol-5-yl hydrazone [l-I. Beyer et al., Ber.89, 2552 (1956)] or by acylation of the appropriate4-ethoxycarbonylpyrazol-5 yl hydrazine with the appropriate acidchloride or acid anhydride while heating, after which the acylatedcompound is heated under reflux with a dry inert solvent, such as,benzene, toluene, etc., and phosphorous oxychloride to cause ringclosure and formation of the desired 7 alkoxycarbonyl 1Hpyrazolo[3,2-c]-s-triazole. Compounds of Formulas I and Ia in which R isa substituted amino group are advantageously prepared by heating theappropriate 4-ethoxycarbony1 pyrazol-S-yl hydrazine with the appropriateisocyanate of the Formula RNCO in an inert solvent, isolating theproduct then ring closing with phosphorous oxychloride, and subsequentlyhydrolyzing the 4-ethoxycarbony1 group from the compound.

Compounds of Formulas I and la, where R is an alkylthio radical, and Ris a branched alkyl or aryl, may also be conveniently obtained byreacting an isothiocarbohydra-zide hydrohalide exemplified by compoundsof the formula such as prepared with the correspondingthiocarbohydrazide and alkyl halide; with a keto ester of the formula RCOCH COOR' at a temperature of about 75 -130 C. to directly obtain thebicyclic intermediate as follows:

EMA

wherein R" is defined as an alkyl group and X is an acid anionpreferably a halide ion (Example: 1'', Br").

The above alternative reaction is more fully disclosed and claimed inour copending application entitled Pyrazole[3,2-c]-s-Triazoles andProcess for the Manufacture Thereof, U.S. Ser. No. 106,892, on January15, 1971.

The term a sensitizing amount, as herein used, has accepted meaning inthe art, a convenient concentration range being about 40-1000 mg. ofsensitizing dye/mold of silver.

The following examples are included for a further understanding of ourinvention.

EXAMPLE 1 7-(6-methyl-3-phenyl 1H pyrazolo[3,2-c]-s-triazol-7-ylidene)methylene-G-mcthyl 3 phenyl-lH-pyrazolo [3,2'c]-s-triazole6-methyl-3-phenyl-1H-pyrazolo[3,2 c]-s-triazole (50 mg.) in acetic acid(2 cc.) is treated with ethyl orthd formate (0.5 cc.). Yellow dyeimmediately forms and on stirring the product, crystallizes. It iscollected by filtration and washed with acetic acid. The dye issuspended in boiling ethanol and after cooling is collected byfiltration and washed with ethanol. The yield of dye is almosttheoretical. The dye is soluble in a mixture of ethanol and aqueouscaustic soda. It has an absorption maximum in pyridine at 483 mi. Thedye sensitizes a silver chlorobromide emulsion out to 565 nm. with apeak at 450 nm. when utilized at a concentration of 200 mg./mole ofsilver.

The following dyes are prepared using procedures similar to thatdescribed in Example 1 with the appropriate intermediates:

7- 6-methyl-3 -p-tolyl-1H-pyrazo1o [3 ,2-c] -s-triazol- 6-ylidene)methylene-6-methyl-3-p-tolyl-1H- pyrazolo [3,2-c1-s-triazole,

7-(6-methyl-3-n-propyl-lH-pyrazolo [3,2-c1-s-triazol-7-ylidene)methylene-6-methyl-3-n-propyl-1H- pyrazolo 3,2-c] -s-triazole,

7- 6-methyl-3-p-methoxyphenyllI-I-pyrazolo 3,2-c] -striazol-7-ylidenemethylene-G-methyl-3-p-methoxyphenyllH-pyrazolo 3 ,2-c] -s-triazole and7-(6-methyl-3-(2,6-dichlorophenyl)-1I-I-pynazolo[3,2-c]-s-triazol-7-ylidene methylene-6-methyl-3-(2,6-dichlorophenyl lH-pyrazolo[3,2-c] -s-triazole.

EXAMPLE 2 7 (3,6 dimethyl 1H pyrazolo[3,2-c] s triazol- 7 ylidene) 3'allylidene 3,6 dimethyl 1H- pyrazolo[3,2-c]-s-triazole 3,6-dimethyl 1Hpyrazolo[3,2-c1-s-triazole (50 mg.) in acetic acid (2 cc.) is treatedwith p-ethoxyacrolein acetal (0.5 cc.). A magenta dye is formedimmediately aand the mixture is warmed on the steam bath for two minutesand after cooling the dye precipitates by addition of ether. The productis collected by filtration and washed with ether. The yield is almosttheoretical. The dye has an absorption maximum in methanol at 542 my andis bleached by a developer, such as, Kodak (a registered trademark) D19Developer.

The following dyes are prepared using procedures similar to thatdescribed in Example 2 with the appropriate intermediates:

7-(6-methyl-3-phenyl-lH-pyrazolo[3,2-c]-s-triazol-7-ylidene)-3-allylidene-6-methyl-3-phenyl-1H pyrazolo[3,2-c]-s-triazole,

7- 6-methyl-3 -p-tolyl-1H-pyrazolo [3 ,2-c] -s-triazol- 7-ylidene -3'-allylidene-6-methyl-3-p-tolyl-1H- pyrazolo[3,2-c]-s-triazole,

7-(6-methyl-3-n-propyl-1H-pyrazo1o[3,2,-c]-s-triazol-7-ylidene)-3'-allylidene-6-methyl-3-n-propyl-1H-pyrazolo[3,2-c1-s-triazole and 7-( 6-methyl-3-p-methoxyphenyllH-pyrazolo3,2-c]-striazol-7-ylidene)-3'-allylidene-6-methyl-3-p-methoxyphenyl-lH-pyrazolo[3,2-c]-s-triazole.

EXAMPLE 3 7-(1,3 diethyl 4,6 dioxo-hexahydro 2 thio pyrimidylidene) 3'allylidene 3,6 dimethyl-1H- pyrazolo[3,2-c]-s-triazole 3,6 dimethyl 1Hpyrazolo[3,2-c]-s-triazole (0.14

gram) and 1,3-diethyl 4,6 dioxo 5 (3-ethoxyallylidene)hexahydro 2thiopyrimidine (0.28 gram) are warmed in ethanol (5 ml.) on a steam bathfor 5 minutes and the magenta dye is precipitated by pouring into water(25 ml.). The product which is obtained in almost theoretical amount iscollected and dried. It has an absorption maximum in methanol at 539 mg.

The following dyes are prepared using procedures similare to thatdescribed in Example 3 with the appropriate intermediates.

7(1,3-diethyl-4,6-dioxo-hexahydro-2-thio-5-pyrimidylidene) 3'-allylidene-6-methyl-3-phenyl-1H- pyrazolo 3,2-c] -s-triazole,

7 (.1,3-diethyl-4,6-dioxo-hexahydro-Z-thio-S -pyrimidylidene) 3-allylidene-6-methyl-3-p-tolyl-1H- pyrazolo [3 ,2-c] -s-triazole,

7(3-phenyl-2-thio-4-oxo-5-thiazolidylidene)-3'-al1ylidene-6-methyl-3-p-methoxyphenyllH-pyrazolo[3 ,2-c] -s-triazole and 7 3-phenyl-2-thio-4-oxo-S-thiazolidylidene-3'-allylidene-6-methyl-3-(2,6-dichlorophenyl) -1H-pyrazolo [3,2-c]-s-triaz0le.

EXAMPLE 4 3-ethyl-2-(3,6-dimethyl-lH-pyrazolo[3,2-c] -s-triazol-7-ylidene -2'-ethylidenebenzthiazoline 3,6 dimethyl 1Hpyrazolo[3,2-c]-s-triazole (0.14 gram) 22'-acetanilido vinylbenzthiazoleethiodide (0.45 gram), triethylamine (0.5 ml.) and ethanol (25 ml.) areheated together on a steam bath for 10 minutes. After cooling, ether (50ml.) is added and the product separates. The yield of dye is 0.1 gram.It has an absorption maximum in methanol a 494 mg.

The following dyes are prepared using procedures similar to thatdescribed in Example 4 with the appropriate intermediates.

EXAMPLE 5 l-ethyl 2,5 dimethyl 3 (3,6 dimethyl 1H pyrazolo[3,2-c] striazol 7 ylidene)methylenepyrrole 3,6 dimethyl 1Hpyrazolo[3,2-c]-s-triazole (0.14 gram) l-ethyl 2,5 dimethyl 3 pyrrolealdehyde (0.12 gram) and acetic acid (1 ml.) are warmed together on asteam bath for 5 minutes to give a yellow dye which is isolated byremoving the acetic acid in vacuo. The dye has an absorption maximum inmethanol at 436 mg and is bleached by a developer, such as, Kodak D19Developer.

The following dyes are prepared using procedures similar to that used inExample 5 with the appropriate intermediates.

1-ethyl-3,5-diphenyl-2-(3,6-dimethyl-1H-pyrazolo [3,2-

0] -s-triazol-7-ylidene methylene-pyrrole,

l-ethyl-3-methyl-2- 3 ,6-dimethyl-1H-pyrazolo[3 ,2-c]-s-triazol-7-ylidene -methyleneindole,

1-ethyl-2-methyl-3 (3,6-dimethyllH-pyrazolo[3 ,2-c]- s-triazol-7-ylidenemethyleneindole,

1-ethyl-2,5-dimethyl-3- 6-methyl-3-phenyllH-pyrazolo [3 ,2-c]-s-triazol-7-ylidcne mcthylene-pyrrole,

1-ethyl-3,5 -diphenyl-2- 6-methyl-3-phenyllH-pyrazolo [3 ,2-c]-s-triazol-7-ylidene methylene-pyrrole,

l-ethyl-3 -methyl-2- 6-methyl-3-phenyllH-pyrazolo[3,2-c]-s-triazo1-7-ylidene) methyleneindole,

1-ethyl-2-methyl-3- 6-methyl-3-phenyllH-pyrazolo [3,2-c] -s-triazol-7-ylidene) methyleneindole, and

7- (6-methyl-3-phenyl-1H-pyrazolo [3 ,2-c] -s-triazol- 7-ylidene) 3'-allylidene-3,6-dimethyllH-pyrazolo [3 ,2-c] -s-triazo1e.

EXAMPLE 6 7 (1,3 diethyl 4,6 dioxo-hexahydro 2 thio 5- pyrimidylidene) 3allylidene 3 p-dimethylaminophenyl-6-methyllH-pyrazolo [3,2-c]-s-triazole The dye is prepared by the method of Example 3 using 3-(2',6dichlorophenyl)-6-methyl-1H-pyrazolo[3,2-c]-striazole instead of3,6-dimethyl 1H pyrazolo[3,2-c]-striazole.

EXAMPLE 83-ethyl-2-(6-methyl3-phenyl-lH-pyrazolo[3,2-c1-s-triazole-7-ylidene)-2-ethylidenebenzoxazoline'6-methyl 3 phenyl-lH-pyrazolo[3,2-c1-s-triazole (0.2 gram),2-2-acetanilidovinylbenzoxazole ethiodide (0.45 gram) and triethylamine(0.42 ml.) in ethanol (20 ml.) are heated together on a steam bath for10 minutes. The mixture is cooled and diluted with water (10 ml.) toprecipitate the product which is recrystallized from aqueous ethanol asorange crystals.

EXAMPLE 9 3-ethyl-2- (6-methyl-3 -phenyl-1H-pyrazolo [3 ,2-c]-s-triazole-7-ylidene) -2-ethylidenebenzthiazoline This compound isprepared from 6-methyl-3-phenyl-1H- pyrazolo[3,2-c1-s-triazole and2-2'-acetanilidovinylbenz thiazole ethiodide in ethanol in the presenceof triethylamine by the method of Example 4.

The product, which is isolated in the form of red platelets, sensitizesa silver chlorobromide emulsion out to 600 nm. with peaks at 510 and 560nm.

EXAMPLE l (6-methyl-3 -phenyl-1H-pyrazolo [3,2-c] -s-triazol-7-yl)methylene-3-phenyl-2-thiothiazolid-4-one 6methyl-3-phenyl-lH-pyrazolo[3,2-c]-s-triazole (0.2 gram),S-ethoxymethylene 3 phenylrhodanine and triethylamine (0.42 ml.) inethanol (20 ml.) are heated on a steam bath for 10 minutes and aftercooling, the reaction mixture is acidified with dilute hydrochloricacid. The separated product is collected by filtration andrecrystallized from benzene as yellow-orange needles.

The product sensitizes a silver chlorobromide emulsion out to 610 nm.with a peak at 570 nm.

The following dyes are prepared using procedures similar to thatdescribed in Example 10 with the appropriate intermediates.

5-(6-methyl-3-phenyl-7H-pyrazolo[3,2-c]-s-triazol-7-yl)methylene-1,3-diethyl-2-thiobarbituric acidmethylene-1,3-diethyl-Z-thiobarbituric acid and 5 3,6-dimethyl-1H-pyrazolo [3 ,2-c] -s-triazol-7-yl)methylene-3-phenyl-2-thiothiazolid-4-one.

The following Examples 11 through 14 illustrate the reactions used tosynthesize compounds of Formulas I and la used in Examples 1 through 10above.

10 EXAMPLE 11 6-methyl-3 -phenyl-1H-pyrazolo[3,2-c1-s-triazole 7ethoxycarbonyl-6-methyl-3-phenyl-lH-pyrazolo[3,2- c]-s-triazole (1 gram)and sulfuric acid (sp.gr. 1.84; 8 ml.) are warmed on steam bath at 60-70C. for 45 minutes. The clear reaction solution is cooled and poured intowater (200 ml.). The thick colorless precipitate is colletced byfiltration, Washed with sulfuric acid (3 N, 25 ml.) and then with water(50 ml.). The product is recrystallized from aqueous ethanol andobtained as bulf needles. The yield is 0.4 gram (55%). C H N requires66.7% C; 5.1% H; 28.3% N; sample on analysis gives 66.8% C; 5.3% H;27.85% N.

EXAMPLE 12 3-p-dimethylaminophenyl-6-methyl-lH-pyrazolo [3,2-c]-s-triazole The method of preparation is similar to Example 11 using theappropriate intermediate. The intermediate used is prepared by reactionof p-dimethylaminobenzaldehyde with 4-ethoxycarbonyl 3methylpyrazol-S-yl hydrazine and ring closure of the resulting hydrazoneby mixing it with sodium acetate in acetic acid and adding to themixture a solution of bromine in glacial acetic acid.

EXAMPLE l3 3,6-dimethyllH-pyrazolo [3,2-c] -s-triazole4-ethoxycarbonyl-3-methylpyrazol 5 yl hydrazine [H. Beyer et al. Ber.89, 2552 (1956)] (3.09 grams) is mixed with acetic acid (10 ml.) andacetic anhydride (1.5 ml.) and heated on steam bath for 1 hour. Thesolution is cooled, poured into water (50 ml.) and the crystallineacethydrazide is collected, after chilling overnight, washed with icecold water and dried. The product which weighs 3.14 grams (98%) MP. C.is heated under reflux with dry benzene (125 ml.) and phosphorusoxychloride (2.7 ml.) for 4 hours and then stood overnight at roomtemperature. The benzene is removed by distillation and the residual oilis stirred with water (100 ml.). The mixture is extracted with ethylacetate (3x ml.). The ethyl acetate solution is dried over calciumsulfate and then concentrated to dryness yielding a pale yellow solid whch is recrystallized from ethanol. The product which weighs 2.05 gramsand melts at 172 3 C. is treated with concentrated sulfuric acid (16ml.) and heated on a steam bath for 75 minutes. The solution is thencooled and poured into water (100 ml.) and, after chilling, is basifiedto pH 10 with 40% sodium hydroxide solution. The solution is extractedwith ethyl acetate (3 150 ml.) and the organic layer separates, is driedover calcium sulfate and, after removing the solvent by distillation, apale yellow solid is obtained. The product weighs 1.1 grams and melts atC.

EXAMPLE l4 3-(2,6-dichlorophenyl)-6-methyl-lH-pyrazolo [3 ,2-c]s-triazole-7-carboxylic acid This compound is synthesized by adding asolution of bromine in glacial acetic acid to a mixture of2,6-dichlorobenzaldehyde 4-ethoxycarbonyl-3-phenylpyrazol-5-yl hydrazoneand sodium acetate in acetic acid. The 2,6-dichlorobenzaldehyde 4ethoxycarbonyl-3-phenylpyrazol-5-yl hydrazone is advantageously producedby reacting 4- ethoxycarbonyl-3-phenylpyrazol-5-yl hydrazine with 2,6-dichlorobenzaldehyde.

Additional precursor compounds suitable for obtaining the dyes ofFormulae HI-VIII (supra) may be produced as follows:

EXAMPLE 15 3-methylthio-6-phenyl-lH-pyrazolo [3,2-c] -s-triazole(Compound 15) Ethyl benzoylacetate (9.6 grams) and S-methylisothiocarbohydrazide hydroiodide (12.4 grams) were heated together at110-l15 C. for 25 minutes. During the last 5 minutes of the heating thevolatile reactants were distilled oil in vacue. The reaction mixture wascooled and then heated with sufficient boiling sodium carbonate solution(about 300 ml.) to effect solution of most of the reaction mass. A smallamount of oily residue remained which was removed by filtration. Oncooling the hot clear carbonate solution the product crystallized andwas collected by filtration. It was recrystallized from benzene as tinybuff-colored needles. The yield of product which melted at 179 C. was 5grams. It coupled with oxidized 2-amino-5-diethylaminotoluene developerto give a dye which had A ethyl acetate at 565 nm. The S-methylisothiocarbohydrazide hydroiodide was prepared by adding methyl iodide(18 grams) to a well stirred suspension of thiocarbohydrazide (12 grams)in boiling ethanol (400 ml.) and heating under reflux for 2 hours. Theproduct was isolated by cooling the hot filtered solution and collectionof the separated product by filtration. Concentration of the ethanolsolution to about half volume gave a second crop. The yield of colorlesscrystals was 70%. The product melted at 145 (with decomposition).

EXAMPLE l6 3-methylthio-6-m'-nitrophenyl-lH-pyrazolo [3,2-c]-striazolell 1 a EXAMPLE 17 6-heptadecyl-3-methylthio-lH-pyrazolo[3,2-c1-s-triazole SCH 1 3 011 N A soltution of ethyl stearoylacetate(2.1 grams) and S-methyl isothiocarbohydrazide hydroiodide (1.6 grams)in n-amyl alcohol (25 ml.) was heated under refiux for 2 hours. Oncooling some solid material separated and Was collected by filtration.Ether was added to the amyl alcohol solution to precipitate more solidmaterial which was also filtered off. Neither solid coupled withoxidized developers. The solution was concentrated to leave an oil whichwas treated with benzene 100 ml.) and the solvent again removed. Theresidual gum (2 grams) coupled with oxidized 2-amino-5-diethylaminotoluene developer to give a dye having 1 ethyl acetate at 541 nm.

12 EXAMPLE 1:;

3-methylthio-6-p-nitrophenyl-1I-I-pyrazolo[3,2-c]-striazole N-N" S OH: uN H OIN Ethyl p-nitrobenzoylacetate (2.26 grams) andS-methylisothiocarbohydrazide hydroiodide (2.36 grams) were heated inboiling amyl alcohol (40 cc.) for 35 minutes. The reaction mixture wascooled and the product which precipitated as yellow crystals wascollected by filtration and recrystallized from amyl alcohol. Thepurified product was collected, washed with ethanol and dried. The yieldof product was melted at 277 C. was 1 gram. It coupled with oxidized2-amino-5-diethylaminotoluene developer to give a dye with A ethylacetate at 588 nm.

EXAMPLE 19 3-methylthio-6-propyl-lH-pyrazolo[3,2-c1-s-triazole Thiscompound was prepared similarly to Example 17 using a proportionateamount of ethyl butyrylacetate instead of ethyl stearoylacetate. Theproduct which was obtained as a gum coupled with oxidized2-amino-5-diethylaminotoluene developer to give a dye with A ethylacetate at 541 nm.

EXAMPLE 20 6,2-furyl-3-methylthio-lH-pyrazolo[3,2-c]-s-triazole Thiscompound was prepared as Example 17 using ethyl- 2furoylacetate insteadof ethyl stearoylacetate. The product which was obtained as a gumcoupled with oxidized 2- amino-5-diethylaminotoluene developer to give adye having A ethyl acetate at 567 nm.

EXAMPLE 21 3,6-di(methylthio)-lH-pyrazolo[3,2-c]-s-triazole NN--"som Nems H EXAMPLE 227-bromo-3-methylthio-6-phenyl-lH-pyrazolo[3,2-c1-striazole Compound 15(1 gram), sodium acetate (0.42 gram) were dissolved in acetic acid (30ml.) and the solution was treated with bromine (0.8 gram) in acetic acid(4 ml.) portionwise. The mixture was allowed to stand at roomtemperature for 40 minutes and then heated on a steam bath for 20minutes, after which it was cooled back to room temperature and pouredinto water ml.) The precipitated product was collected by filtration,washed with water and dried. It weighed 1.1 grams, melted at 152-153 andcoupled with oxidized 2-amino-5-diethylamino toluene developer to give amagenta dye.

13 EXAMPLE 237-chloro-3-methylthio-6-phenyl-1H-pyrazo1o[3,2-c]-striazole N-N"S CH:

as N

Compound 15 (1 gram) was dissolved in acetic acid (15 ml.) and sulphurylchloride (0.65 gram) were slowly added to the solution, the mixture washeated on the steam bath for minutes and allowed to stand at roomtemperature for 1 hour. The mixture was then poured into water (200 ml.)and the precipitated product was collected by filtration and dried. Itweighed 0.9 gram and melted at 150.

EXAMPLE 24 7 (3 methylthio-'6-phenyl-7H-pyrazolo[3,2-c]-s-triazol- 7ylidene)-rnethylene-3-methylthio-6-phenyl-lH-pyrazolo[3,2-c]-s-triazoleuHa N CHaS \N/ Compound 15 (0.1 gram), ethylorthoformate (1 ml.) andacetic acid (4 ml.) were heated at boiling point for 5 minutes. Theproduct which crystallized from the hot reaction mixture was isolatedafter cooling by filtration. It was washed with ethanol, dried andobtained in almost theoretical amount. It has an absorption maximum inmethanol in the presence of triethylamine at 494 nm.

=EXAMPLE 25 7,3 (3 methylthio-6-phenyl-7H-pyrazolo[3,2-c]-s-triazol 7ylidene)allylidene-3-methylthio-6-phenyl-1H- pyrazole[3,2-c]-s-triazole(Compound 25) A solution of Compound 15 (0.23 gram) and1,1,3-trimethoxy-3-ethoxypropane (0.2 ml.) in acetic acid (5 ml.) washeated under reflux for 2 minutes. The solid dye product separated fromsolution and after cooling it was collected and recrystallized in almostquantitative yield from methanol. The product was obtained as dark greenmetallic crystals A methanol at 554 nm.

Compound 15 (0.23 gram), 2 ethylthiobenzthiazole ethiodide (0.34 gram),triethylamine (0.5 ml.) and ethanol (5 ml.) were heated under reflux for10 mins. After chilling the reaction mixture, the separated dye wascollected and recrystallized from ethanol as pale yellow crystals. Itweighed 0.1 gram and had 71 methanol at 410 nm.

EXAMPLE 27 3-methylthio-7-p-nitrobenzylidene-6-phenyl-7H-pyrazolo[3,2-c1-s-triazole CeHs I N CH; S

Compound 15 (0.23 gram), p-nitrobenzaldehyde and acetic acid (5 ml.)were heated under reflux for 10 mins. After cooling the product wasprecipitated by dilution with water (25 ml.) and collected byfiltration. It was twice recrystallized from ethanol and obtained in 20%as pale yellow crystals. It coupled with oxidized 2-amino-5-diethylamino toluene developer to 'give a dye A ethyl acetate at 566 nm.

EXAMPLE 28 7-( 1-ethyl-2,5-dimethyl-3-pyrryl) methylene-3-methylthio-6-phenyl-7H-pyrazolo[3,2-c] -s-triazole Compound 15 (0.46 gram),1-ethyl-2,5-dimethylpyrrol- 3-aldehyde (0.3 gram) were dissolved inboiling ethanol (10 ml.) and triethylamine (1 ml.) was added and thesolution was refluxed for 10 minutes. The solution was concentrated to 5ml. and well chilled when the dye product (0.25 gram) separated. It wastwice recrystallized from methanol giving 0.15 gram orange needles. Thedye has A methanol at 447 nm.

EXAMPLE 29 5 (3 methylthio-6-phenyl-lH-pyrazolo[3,2-c]-s-triazol- 7yl)methylene-3-phenyl-2-thiothiaz0lid-4-one (Compound 2.9)

A mixture of Compound 15 (0.23 gram),S-ethoxymethylene-3-phenylrhodanine (0.26 gram), triethylamine (0.42ml.) and ethanol (20 ml.) was heated under reflux for 10 minutes. Abouthalf the ethanol was removed by distillation, water (10 ml.) added, andthe mixture made slightly acid with hydrochloric acid. The dyeprecipitated as a gum which rapidly hardened. After collection byfiltration the product was recrystallized from a mixture of benzene andpetroleum ether. The dye which was obtained in 55% yield had A methanolat 495 nm.

1 EXAMPLE 3o 3-ethyl-2,2'-(3-methylthio-6-phenyl-1H pyrazolo[3,2-c]-s-triazole-7 ylidene)ethylidenebenzoxazoline (Compound 30) 3-ethyl-2,2(3-methylthio-6-phenyl-7H-pyrazolo[3,2-c1- s-triazol-7ylidene)ethylidenebenzthiazoline (Compound 31) C H- C H: C

I N C n;

CH: S

Compound 15 (0.46 gram) 1 2,2'-acetanilidovinylbenzthiazole ethiodide(0.9 gram), triethylamine (1 ml.) and ethanol (30 ml.) were heatedtogether on a steam bath for minutes. The reaction mixture was cooledand the separated product was collected by filtration. It wasrecrystallized twice from methanol. The purified product weighed 0.2gram and has A methanol at 521 nm.

EXAMPLE 32 7,3'-(l,3-diethyl 4,6-dioxo-hexahydro-2-thiopyrimid-5-ylidene)allylidene 3-methylthio-6-phenyl-ll-I-pyrazolo[3,2-c]-s-triazole Compound (0.46 gram) and 1,3-diethyl-4,6-dioxo- 5-(3-ethoxyallylidene) hexahydro-Z-thiopyrimidine (0.56 gram) weredissolved in boiling ethanol ml.) and the mixture was refluxed for 10minutes. The reaction mixture was cooled and the dye was collected byfiltration. The product was purified by dissolving it in hot pyridineand reprecipitating by the addition of ethanol to the cooled pyridinesolution. The product which weighed 0.4 gram had A methanol at 535 nm.and 561 nm.

16 EXAMPLE 33 3-ethyl-2,4' (3-methylthio-6-phenyl-7H-pyrazolo[3,2-c]-s-triazol 7-ylidene) but-2 enylidenebenzthiazoline (Compound 33)Compound 15 (0.46 gram), 2,4-acetanilidobutadienylbenzthiazole ethiodide(0.95 gram) were dissolved in boiling ethanol (70 ml.). Triethylamine (1ml.) was added and a deep blue dye was formed. The mixture was heatedunder reflux for 5 minutes and on chilling dark blue needles separated.The product (0.6 gram) was collected and recrystallized twice frommethanol. The dye had x methanol at 619 nm.

EXAMPLE 34 A sensitizing amount (i.e. 200 mg./mole of silver) of each ofdye compounds 25, 30, 29, 31, 26 and 33 indieated in the table below wasadded to separate portions of a negative-type, developing out gelatinosilver chlorobromide emulsion. Each of these emulsions was coated onto apiece of cellulose ester film support and dried. Spectrographicexposures were made on each coating and these were developed in aphotographic developer having the following compositions:

Garms p-Methylaminophenol sulphate 2.0 Sodium sulphite desiccated 90.0Hydroquinone 8.0 Sodium carbonate monohydrate 52.5 Potassium bromide 5.0

Water to make 1 liter.

fixed in a conventional sodium thiosulphate fixing bath, washed, anddried. The following table summarizes the wavelength of light to whichthe maximum sensitivity is produced, and the longest wavelength light towhich each emulsion is sensitized.

Wavelength of light in nm. to which- (i) Dye produces (ii) Dyesensitizes max. sensitivity emulsion at- Compound No.:

EXAMPLE 3S 6-heptadecyl-3-methylthio-1H pyrazolo[3,2-c]-s-triazole (0.2gram) was dissolved in dibutyl phthalate (0.4 ml.) at C. A hot solution(80 C.) of 10% inert bone gelatin (12.8 ml.) and 5%tri-isopropylnaphthalene sulphonate (1.2 ml.) were added to the couplersolution and the mixture was homogenized using an ultrasonic probe.Water (8.8 ml.) and 7.5% solution of saponin (0.9 ml.) were added andthe mixture was filtered. A gelatino bromoiodide emulsion (6.8 gramscontaining 0.69 gram silver) was added to the filtrate and the mixturewas coated on a cellulose acetate film base at 425 m. gelatin/sq. ft.dry weight and the lightsensitive material so obtained was exposed andthen de- 17 veloped for 10 minutes at 58 F. in a color developer of thefollowing composition:

Water ml 800 Anhydrous sodium sulphite 2.0

2-amino-5-diethylamino-tdluene hydrochloride gr 2.0

Sodium carbonate monohydrate gr 20.0

Sodium bromide gr 1.73

Water to make 1,000 ml. and pH adjusted to 10.9

The development was followed by acid stop-fix, ferricyanide bleach andfinally fixation stages when a magenta image was formed in the exposedregions by the formation of a dye having an absorption maximum at 559nm. Other developing agents can be used for example,3-methyl-4-amino-N-fi methyl sulphonamidoethyl-N- ethylaniline gives adye with absorption maximum at 555 nm.

Compound 5 (in ethanol sufficient to dissolve coupler 1.5 Water to 1liter.

pH adjusted to 11.5 with sodium hydroxide solution was used to colordevelop a magenta image in a strip of image exposed film coated with alayer of silver halide emulsion. The silver in the strip was convertedto silver halide by treating it with a ferricyanidebromide bleach andthen the silver halide was removed by treating the strip with a hypofixbath to leave a magenta dye image having an absorption maximum at 557nm. A magenta dye image having an absorption maximum at 570 nm. wasobtained when 3-methylthio-6-phenyl-H pyrazolo[3,2-c] s-triazole(Compound 15) is used as the coupler and N,N-diethyl-p-phenylenediamineas the developing agent in the above formula.

Our dyes, especially those of Formulas III, VI and VIII are usedadvantageously as spectral sensitizers for photographic silver halideemulsions when incorporated therein. Dyes of Formula IV are used toadvantage in hydrophilic colloid light-absorbing filter layers forphotographic elements. These dyes are bleached by the action ofconventional developer solutions.

The sensitizing dyes of our invention are especially useful forextending the spectral sensitivity of the customarily employed silverchloride, silver chlorobromide, silver bromide, silver bromoiodide andsilver chlorobromoiodide developing out emulsions using a hydrophiliccolloid carrier such as gelatin, its water-soluble derivatives,polyvinyl alcohol, its water soluble derivatives and copolymers,water-soluble vinyl polymers, such as polyacrylamide, imidizedpolyacrylarnide, etc., and other water-soluble film-forming materialsthat form water-permeable coatings, such as colloidal alubumin,watersoluble cellulose derivatives like ethanolamine cellulose acetate,etc. To prepare emulsions sensitized with one or more of our new dyes,it is only necessary to disperse the dye or dyes in the emulsions. Themethods of incorporating dyes in emulsions are simple and well known tothose skilled in the art. In practice, it is convenient to add the dyesto the emulsion in the form of a solution in a suitable solvent.Methanol, ethanol, propanol, etc., acetone and pyridine are used toadvantage. The dyes are advantageously incorporated in the finished,washed emulsions, and should be uniformly distributed throughout theemulsions.

The concentration of the dyes in the emulsions can vary widely, and willdepend upon the type of emulsion and the effect desired. The suitableand most economical concentration for any given emulsion will beapparent to those skilled in the art, upon making the ordinary tests andobservations customarily used in the art of emulsion making.

To prepare a hydrophilic colloid-silver halide emulsion sensitized withone or more of our new dyes, the follow ing procedure is satisfactory. Aquantity of dye is dissolved in a suitable solvent, such as an alcohol,acetone, pyridine, etc., and a volume of this solution, which may bediluted with water, containing the dye, is slowly added to about 1000cc. of gelatino-silver halide emulsion, with stirring. Stirring iscontinued until the dye is uniformly dispersed in the emulsion.

The above statements are only illustrative, as it will be apparent thatthe dyes can be incorporated in photographic emulsions by any of theother methods customarily employed in the art, e.g., by bathing a plateor film upon which an emulsion is coated in a solution of the dye in anappropriate solvent. However, bathing methods are ordinarily not to bepreferred. Emulsions sensitized with the dyes can be coated on suitablesupports, such as glass, cellulose derivative film, resin film or paperin the usual manner.

EXAMPLE 37 A sensitizing amount of each of the dyes indicated in thetable below is added to separate portions of an ordinary gelatino silverchlorobromide emulsion. Each of these emulsions is coated on a piece ofcellulose ester support and dried. Spectrographic exposures are made atsecond on each coating and these are developed at room temperature in aphotographic developer having the composition:

Grams p-Methylaminophenol sulfate 2.0 Sodium sulfite, desiccated 90.0Hydroquinone 8.0 Sodium carbonate-H O 52.5 Potassium bromide 5.0

Water to make 1 liter.

fixed in a conventional sodium thiosulfate fixing bath, washed anddried. The following table summarizes the wavelength of light to whichthe maximum sensitivity is produced and the longest wavelength light towhich each emulsion is sensitized.

Wavelength of light in mm.

to which- 111 the presence of Leucophor B (a registered trademark)brighteuera Similar results are obtained when Example 15 is repeatedusing other silver halide emulsions. Similarly it can be shown thatother of our dyes such as those listed immediately after Examples 1, 3,4, and 10 are valuable spectral sensitizers for photographic silverhalide emul- $10118.

Our novel spectrally sensitized silver halide emulsions areadvantageously used in making color photographic elements that are colordeveloped with color developers that contain the color-forming couplersor used in making color photographic elements that incorporate thecolor-forming couplers in the emulsions. Any of the cyan, yellow andmagenta dye-forming couplers used in color photography are used toadvantage to form a dye image in our emulsions.

1 9 EXAMPLE 3:;

A batch of aqueous gelatin is divided into 6 portions to which samplesof the dyes of Examples 1, 2, 3, 5, 25, and 28 are added. The dye ofExample 1 is added in pyridine solution while the dyes of Examples 2, 3,5, 25, and 28 are added in methanol solution. The dyed portions ofaqueous gelatin are coated on pieces of film support as useful filterlayers for photographic elements.

The invention has been described in detail with particular reference tocertain preferred embodiments thereof, but it will be understood thatvariations and modifications can be effected within the spirit and scopeof the invention.

We claim:

1. A photographic element comprising a support containing coatedthereon, at least one light-sensitive hydrophilic colloid emulsion layerand at least one layer containing a filter dye having the formula:

wherein R and R each represent a member selected from the classconsisting of hydrogen, alkyl, aryl, heterocyclic, amino, acylamido,hydroxyl, alkoxyl, carboxy, and esterified carboxy groups, and Qrepresents a =OH-(LL-),,

in which R, is an alkyl or a phenyl group; L is defined as a methinegroup; n is an integer of from to 2; Z represents the atoms necessary tocomplete a heterocyclic basic nucleus having from 5 to 6 atoms in theheterocyclic ring; and X represents an acid anion.

2. A photographic element as in claim 1, wherein said light-sensitivehydrophilic colloid emulsion layer contains said filter dye.

3. A photographic element as in claim 1, wherein said layer containingsaid filter dye and said emulsion layer differ.

4. A photographic element as in claim 2, wherein said filter dye is 1ethyl 2,5 dimethyl-3-(3,6-dimethyl-1H-pyrazolo[3,2-c]-s-triazol-7-ylidene)methylenepyrrole.

5. A photographic element as in claim 3, wherein said filter dye islethyl-2,5-dimethyl-3-(3,6-dimethyl-1H-pyrazolo[3,2-c]-s-triazol-7-ylidene)methylenepyrrole.

6. A photographic element as in claim 2, wherein said filter dye is 1ethyl 3,5 diphenyl-2-(3,6-dimethyl-1H- pyrazolo [3 ,2-c]-s-triazol-7-ylidene methylenepyrrole.

7. A photographic element as in claim 3, wherein said 20 filter dye is1- ethyl- 3,5 -diphenyl-2-(3,6-dimethyl-1H-pyrazolo[3,2-c]-s-triazol-7-ylidene)methylenepyrrole.

8. A photographic element as in claim 2, wherein said filter dye is 1ethyl 3methyl-2-[3,6-dimethyl-1H-pyrazolo[3,2-c]-s-triazol-7-ylidene)methyleneindole.

9. A photographic element as in claim 3, wherein said filter dye is 1ethyl 3 methyl-2-(3,6-dimethyl-1H-pyrazolo [3 ,2-e] -s-triazol-7-ylidenemethyleneindole.

10. A photographic element as in claim 2, wherein said filter dye is 1ethyl 2-methyl-3-(3,6-dimethyl-1H- pyrazolo- 3,2-c] -s-triazol-7-vadene)methyleneindole.

11. A photographic element as in claim 3, wherein said filter dye is 1ethyl 2 methyl-3-(3,6-dimethyl-1H- pyrazolo [3 ,2-c]-s-triazol-7-ylidene methyleneindole.

12. A photographic element as in claim 2, wherein said filter dye is1-ethyl-2,5-dimethyl-3-(6-methyl-3-phenylll-I-pyrazolo[3,2-c]-s-triazol-7-ylidene)methylenepyrrole.

13. A photographic element as in claim 3, wherein said filter dye is1-ethyl-2,5-dirnethyl-3-(6-methyl-3-phenyl-1H- pyrazolo [3 ,2-c]-s-triazol-7-ylidene) methylenepyrrole.

14. A photographic element as in claim 2, wherein said filter dye is1-ethyl-3,5-diphenyl-2-(6-methyl-3-phenyllH-pyrazolo[3,2-c]-s-triazol-7-ylidene)methylenepyrrole.

15. A photographic element as in claim 3, wherein said filter dye is 1ethyl 3,5-diphenyl-2-(6-methyl-3- phenyl 1Hpyrazolo[3,2-c]-s-triazol-7-ylidene)methylenepyrrole.

16. A photographic element as in claim 2, wherein said filter dye is 1ethyl-3-methyl-2-(6-methyl-3-phenyl- 1Hpyrazolo[3,2-c]-s-triazol-7-ylidene)methyleneindole.

17. A photographic element as in claim 3, wherein said filter dye is1-ethyl-3-methyl-2-(6-methy1-3-phenyl- 1Hpyrazolo[3,2-c]-s-triazol-7-ylidene)methyleneindole.

18. A photographic element as in claim 2, wherein said filter dye is1-ethyl-2-mcthyl-3-(6-methyl-3-phenyllH-pyrazolo[3,2-c]-s-triazol-7-ylidene)methyleneindole.

19. A photographic element as in claim 3, wherein said filter dye is1-ethyl-2-methyl-3-(6-methyl-3-phenyl- 1Hpyrazolo[3,2-c]-s-triazol-7-ylidene)methyleneindole.

References Cited UNITED STATES PATENTS 3,758,309 9/1973 Bailey et al.96-89 R 3,615,639 10/1971 Carpenter et al. 96101 2,887,480 5/1929Webster et a1 96-132 3,598,595 8/1971 Mee et al 96132 NORMAN G. TORCHIN,Primary Examiner E. C. KIMLIN, Assistant Examiner U.S. Cl. X.R.

325 UNITED STATES PATENT OFFICE I RT FIQATEQ C T- Patent No. 3,810,761Dated May 14 1974 lnventoz-(s) Joseph Bailey, Edward B. Knott and PeterA. Marr It. is certified that error appears in the aboveidentifiedpatent and that said Letters Patent are hereby corrected as shown below:

1'" I v Page 1 Column 1, line 37, "sensitizer" should read-'--sensitizers---;

Column 1, line 53, after "coated", "the" should be deleted;

Column 3, lines 5-6, that part of the formula reading "sulfobenzamino"should read su1fobenzamid o--;

Column 3, after.line 24; the first line of the paragraph beforethe'formulae should read ---Our dyes are demonstrated by theformul'ae:--;

Column 3,, line 40, that part of the forx nula reading:

H=(L shouldread I -'CH=(L Column 4-, line 29, "7-chlorobenothiazole"Should read 7-chlorob'enzothiazole--- Column 5,-line 25, "or" shouldread --of, Column 6, line 20, that part of the formulajreading"triazolo" should read--triazole--;

Column 8, line 32, "a" should read --at--;

Column 12,, line 18, after "product", "was"" should read --'which-,--

Column 12, line 54', after the formula, the following paragraph shouldbe inserted: O-vethyl- Smethyl assymmetric' diethiomalonate (1.78 grams)fl(Laaks o, Suomen Kemistilehte, 1944, 17B l-6) and S-methylis0thiocarbo- "(continued on nextpage) 535;? I iUNITED STATES PATENTOFF-ICE QEBfljlEIflATE OF CORRECTION Patent No. 3 81O,761 Dated 14; 1974Joseph Bailey, Edward B. Knott and :Peter A. Marr Inventor(s) It iscertified that error appears in the above-identified Patent 7 and thatsaid Letters Patent are hereby corrected as shown below:

hydrazide (2:36 grams)v were heated in boiling amyl alcohol (25 ml.) for30 minutes and worked up as in Example. 3.

The product which was obtained as a gum coupled with oxidized2-amino-Sdiethylamino toluene developer to give a dye having Amax ethylacetate at 533 nm.

Column 13; line 4 2, that part of the formular'eading 'pyrazole'f,should read pyr'azol-o-;-t--

,Column. l3 lin e 63-65, that part of thehforniula reading:

n d I h 1d iv =C P 5 cu rea 1 "'3 ff I Jo-lumn line 1 "58?" should read68.

Column 17., line. 4.0, that-part of the form ula reading "'-H-" shouldread -lH-' Column 19, line 16, before "coated", should be inserted; 1

Co lumn 206,}:lihefl4, thatpart of the formula reading sh ul r ---(3 t ai a Column Z'O'Jlin'e ll, that part of the formula reading "vadene";should read yliden'e---; I

Signed and sealedthis 7th day of January 1975.

(SEAL) Attest:

' McCoy-M. GIBSON JR. 6 I MARSHALL- I'D-ANN Attesting Of ficer IComissionjerfof Patents

